Conductive particulate films fabricated by electrospray deposition of candle soot suspensions with acid treatment

[Display omitted] •Synthesis of conductive soot film by electrospray technique.•Enhancement of electrical conductivity of soot film after acid treatment.•Higher surface roughness contributes to increase electrical conductivity of soot film. The electrical properties of carbon-based materials have attracted significant interest due to their wide range of potential applications. This study investigated the effect of nitric acid treatment on the electrical conductivity of candle soot particle films. Electrospray deposition was used to deposit the candle soot dispersion on a solid substrate. The electrical conductivity of the films increased as the concentration of nitric acid increased, with the highest conductivity of 27.65 S cm−1 observed in the film treated with 5 M nitric acid. The increase in conductivity was attributed to the enhancement of interparticle bonding between soot particles after acid treatment. Functional groups such as carboxylic or nitro groups were observed in the films by Fourier transform infrared (FTIR) spectroscopy. Raman spectroscopy showed a broadening of the D bands, suggesting a defect in the crystalline structure due to the formation of functional groups on the soot structure. These results suggest that nitric acid treatment can be used to improve the electrical conductivity of candle soot particle films.